Soundtraxx Micro Tsunami HO Steam Installation | Tech News at Tony's Train Exchange.

One of my favorite brass locomotives is a factory painted Atlantic (4-4-2) in Daylight colors. It is a high stepping fun to watch this locomotive. It somehow got pushed back as I converted to DCC. I've always wanted to install a sound decoder in this locomotive, but how do you put a speaker in a Vanderbilt tender without pulling it apart and repainting? I've asked a number of decoder installers about the Vanderbilt tender and the answers were always discouraging. When I got the Micro-Tsunami to review, a little light went off! Would it be possible to install the decoder and speaker both in the engine and not modify the tender?

The Micro-Tsunami has the same 22 sounds of its bigger brother, the standard Tsunami. The only big change, or should I say small change is the size and power ratings. The Micro-Tsunami has a 0.750 A motor rating and the standard is 1.00 A. The 4-4-2 had a "can" motor and low current draw so the micro would work. Would it fit? The micro is 1.00" long by 0.5" wide and only 0.22" high. The Micro-Tsunami comes with a 220µF 25V capacitor.

The standard Tsunami is on the left and the Micro on the right.

I'm glad to see that small decoders are rated by the power they can handle and not that they are N or HO scale. I've seen an "N" scale sound decoder put into small On3 locomotives.

I pulled the engine apart and did a little measuring and the decoder would fit on top of the motor. The back of the boiler has a full back-head that further limited the usable space in the body shell. There was a weight in the front that almost filled the smoke box. With this weight removed the American Hobby Mini-Oval speaker and enclosure would just fit. One other item was the headlight. There never was a lamp in the headlight casting.

The micro would just fit above the motor and was
taped in place with Kapton tape.

The headlight casting was drilled out and one of the tiny surface mount white LEDs was installed. The LED was held in place with Micro Kristal Klear and wires ran into the boiler. The speaker was wired. The decoder, speaker and LED were all tested with an NCE decoder tester before the installation. I used a Miniatronics 4 wire connector between the body shell and the frame. Two 1/4 oz weights were fitted into the boiler to compensate for removed weight. Then the body shell and frame were put together. Somehow I got the feeling that I was putting 10 pounds in a 5 pound bag! It all fit, there was even room for the capacitor under the motor near the axle.

The Atlantic is certainly a hi-speed passenger locomotive and not one from pulling a long string of cars.

With such a small speaker and decoder, my concern was the volume level with the speaker in the boiler and the only way the sound could escape was in the opening for the drive mechanism. Much to my surprise the sound level was fine, even too loud and the volume level had to be reduced for a number of items including the bell. Since the engine is oil fired, Fireman-Fred-shoveling-coal volume was set to "0".

The quality of the 16-bit sound is one of the outstanding features of the Tsunami line. The Micro has inherited the same fine sound qualities as the larger Tsunami.

The Micro-Tsunami has the same whistle combinations available as the larger Tsunami.

Out on the layout the 4-4-2 Atlantic showed that it was a race horse and not a plow horse. This is a neat engine to watch as it glides across the layout and now with sound!